Generally, a combustion system that uses fossil fuels such as gas, coal briquettes, and oil as a main fuel source is being used as a system for roasting food ingredients such as meat and fish. However, problems of the combustion system using fossil fuels, such as wasted energy and environmental pollution, have been highlighted, and there has recently been a demand to replace the combustion system using fossil fuels with a combustion system using an eco-friendly fuel source instead of fossil fuels.
To meet such demand, U.S. Pat. No. 6,223,737 related to a pellet fuel burning device proposes a configuration in which, when corn kernels (100) are fed into an auger device (70), which is rotated by a motor (78) and gear arrangement (79), through a hopper (68), the auger device (70) may deliver the corn kernels (100) to a pellet burner unit (50) disposed in a fire box (30), and air blown through a pressure box (82) may be supplied to the pellet burner unit (50), thereby igniting the corn kernels (100).
However, in the above-described pellet fuel burning device, because sawdust, paper, wood chips, and the like are accumulated in a lower part of the fire box (30) and then a user manually ignites the accumulation, causing the corn kernels (100) to be initially burned, there is a problem in that a long time is taken for the initial burning and it is thus inconvenient.
Also, as the size of the pellet burner unit (50) increases, accumulation of supplied pellet fuel tends to be focused on one spot, and accordingly, there is a problem in that, during heat transfer, the heat transfer is not uniform or the heat transfer is impeded.